Today’s Question: Once a RAW file has been interpreted as pixels and is open in Photoshop, won’t it be degraded if the Camera Raw filter is applied to these pixels?
Tim’s Quick Answer: It would be fair to say that a direct adjustment using the Camera Raw filter in Photoshop after converting a RAW capture would represent a “destructive” adjustment, by virtue of altering actual pixel values. That said, in some cases this approach provides a helpful solution to an issue with a photo.
More Detail: If you are working with a RAW capture, it is generally best to apply most of your adjustments during the initial RAW processing (such as in Adobe Camera Raw) in order to maximize the benefits of the original RAW data. But it can also be helpful to make use of the Camera Raw filter after the capture. While adjustments that affect pixel values directly can be fairly referred to as “destructive” in terms of altering those pixel values, that doesn’t make those adjustments automatically “bad”.
I generally prefer to take a non-destructive approach to optimizing my photos. I use Lightroom (or Adobe Camera Raw) to process my initial RAW captures, and when I want to apply further adjustments in Photoshop I will use an adjustment layer if that is an option for the type of adjustment I want to apply.
For adjustments that involve the direct manipulation of pixel values, such as using the image cleanup tools in Photoshop, I prefer to use an image layer separate from the underlying Background image layer in order to maximize the flexibility of my workflow.
In this way, it is possible to use the Camera Raw filter in a more flexible way than simply adjusting pixel values directly. You could, for example, create a copy of your Background image layer and apply the Camera Raw filter to that duplicate layer. You could also convert the image layer to a Smart Object by choosing the “Convert for Smart Filters” command on the Filter menu. This will cause any filters (including the Camera Raw filter) to be applied as a Smart Filter, so that you are effectively using the filter as something of an adjustment layer. In other words, the pixel values aren’t being altered directly, and you can return to your adjustments at any time.
For adjustments such as noise reduction, chromatic aberration removal, or perspective correction, it isn’t critical to work with the original RAW capture. Thus, if you neglected to apply these types of adjustments during the initial RAW capture, it is perfectly fine to apply them later in your workflow using the Camera Raw filter. Again, my preference would be to include those adjustments as part of the initial workflow of processing my RAW capture, but if I neglected to apply certain adjustments it is often easier to use the Camera Raw filter than to return to the original capture again. And with many adjustments, the difference in image quality between processing the RAW capture with Adobe Camera Raw and processing the image with the Camera Raw filter will be minimal.